Once doubted as contenders, this never-say-die San Francisco 49ers team isn't laying down for anybody and, in fact, they're picking up steam as they make their bid for a postseason slot.

The timing has been as pictured, as this is beginning to look like the "get healthy, get hot" team approaching the back half of December. Despite road games and treacherous competitors, the 49ers have pocketed four straight wins, which largely appears to be a byproduct of this team getting all the pieces back into the puzzle.

With all his receivers back and a mostly-healthy offensive line, quarterback Colin Kaepernick is looking like his old self again, which is to say the charismatic improv specialist of 2012.

Since Kap's game was the final tumbler that had to fall into place for this team to become scary again in the winter months, it makes the fashion of this past win all the more topical. With impenetrable defense, now coupled with high-powered offense, what is the team really capable of?

Moving to 10-4 on the season, here are some of the key takeaways from San Francisco's 33-14 win over Tampa Bay heading into next week.

49ers Defense Is Stingy

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Come playoff time, the 49ers defense should be this team’s ace in the hole because no matter what, they compete hard and keep this offense in games. From the defensive line on back, they are as impermeable as any.

That’s championship-caliber play. On Sunday versus the Tampa Bay Buccaneers, who field a competitive offense, the 49ers defensive unit went on to underscore its level of consistency. They went across country, playing an early game out of their time zone and stomped this offense out.

And this was a sleeper team. The Bucs were putting up points in recent weeks and there was not a whole lot of film on them, considering the new faces in the lineup. This was San Francisco demonstrating the strength of their scheme and that they are not one to fall victim to trap games either.

They always prepare and they always show up.

From the veteran stars to the developmental undrafted free agents, they’re dependable, through and through.

Even more so, their front seven is arguably the best in all of football. They have a monster of a defensive tackle, the best corps of four linebackers in the world and depth galore. As a whole, this unit thrives on the play from the front seven, which kills all plays up front before they even start.

Run plays or pass plays, it doesn’t matter. They win up front in the box.

Here's the list of quarterbacks I'm afraid to see the 49ers defense play:

The Secondary Is Sneaky Good

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Continuing on this hulking defense the 49ers possess, it seems their secondary is criminally underrated.

Either for their ongoing injuries, lack of star power, the failed experiment with cornerback Nnamdi Asomugha or a direct comparison to the elite secondary of the NFC West rival Seattle Seahawks, the Niners defensive backfield does not get its fair due.

According to the Pro Football Focus grading system, it is actually the No. 3-rated pass defense in the NFL. In terms of yards allowed per game, the 49ers are the fourth-ranked pass defense, also allowing one of the lowest averages in the league on a per-attempt basis.

They’ve benefited from breakout campaigns by Tramaine Brock and Eric Reid, along with a statement season by veteran strong safety Donte Whitner. The unit also receives tremendous support from Tarell Brown and Carlos Rogers—both of whom have played at a Pro Bowl level in recent seasons.

It is a very dense unit and, in tandem with this front seven, the 49ers defense looks like one of the most polished in the NFL heading toward the postseason.

Veteran move by rookie Eric Reid to drop down after that interception and not run in for a TD. It saves his teammates a kickoff; defense too

Dangerous Body of Weapons

When it’s all said and done, tight end Vernon Davis, running back Frank Gore and wide receiver Anquan Boldin are going to be a few of the all-timers at their respective positions.

On Sunday, Vernon Davis became the first tight end in NFL history to notch two seasons with 12-plus receiving touchdowns (13 in 2009), per the team’s Public Relations Director Bob Lange. A week prior, Anquan Boldin became just the 30th player ever to record 11,000 receiving yards in a career.

Entering Week 16, Boldin will be just 42 yards away from his first 1,000-yard season since 2009, which was his last year with the Arizona Cardinals.

Versus Tampa Bay, in his home state, 49ers star tailback Frank Gore passed the 1,000-yard mark for the seventh time in nine seasons. He is only the 20th running back in NFL history to accomplish such a feat, and now currently ranks No. 30 on the all-time rushers list.

He is one of the best at his position ever, and certainly the best this franchise has had in its prestigious history.

Then you have Michael Crabtree who, debatably, was the greatest receiver all-time in college football and is just now beginning to hit his stride as a pro. Better yet, he’s the one with a very unique chemistry with the team’s prodigy behind center. Altogether, this is an ideal foundation of weapons for a playoff run.

It truly seems that Boldin, a solid No. 2 receiver, was the missing link from the past two postseason appearances.

On Sunday they were all clicking, firing in unison, which must’ve sent chills down the spines of fellow NFC contenders.

Offensively, this full-court press by the 49ers with all of their playmakers contributing in confluence makes this offense very threatening all of a sudden. Teams can’t stack the box and they can’t double team anymore. When it comes to defending this offense now, there are far less option because whatever a defense sacrifices, this unit is equipped to take advantage of.

They’ve survived on power rushing and play action for the duration of 2013, but now they can spread it out.

Is LaMichael James Being Worked in More?

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A lot has been said regarding the status of second-year running back LaMichael James and how the 49ers value him.

Well, as the regular season inches toward crunch time, it seems as if the MCL injury he suffered in preseason is what actually set him back. The 49ers do have plans to get him touches in this offense, as he received a couple notable carries Sunday, averaging 11.0 yards per attempt, and lined up as a receiver on several occasions.

One has to take into consideration: not only was James being worked back in health-wise but also from a systematic standpoint. This offense is still in the developmental stages when it comes to its scat backs. This is a power-rushing team with not much of a stretch or screen game to speak of.

But James is an explosive open-field runner and adds a dynamic element that the 49ers offense would be without otherwise.

Furthermore, with his quick bursts on special teams and his high yards-per-carry average, he is becoming harder to ignore. He has finally become a surefire active body on game day and now he is vying for touches.

That being said, if the 49ers happen to have any secret plays they haven’t revealed yet this season, there is a good chance LaMichael James is involved.

Before that it was nice to see @LaMichaelJames get a very productive touch.

Offense Is Inconsistent, Red-Zone Struggles Continue

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When it comes to situational football, the 49ers offense has struggled for these past three seasons. However one aspect of that, third down conversions, has been remedied by the play-making ability of Colin Kaepernick and Michael Crabtree, as well as short-yardage running from Frank Gore.

They’ve certainly improved. But one of the areas where the 49ers continue to come up short is in the red-zone.

It almost hurt them this past weekend versus the Tampa Bay Buccaneers, who were in the game for roughly three quarters. In addition to going 6-of-15 on third-down situations, the 49ers went 1-of-4 in the red zone. Settling for field goals in tight scoring situations has allowed teams to stick around.

While they play great defense and special teams, and manage to get down the length of the field pretty consistently, they lock up in the red zone.

This is an area where they need to become more proficient or else better-scoring teams will take advantage in the postseason.

This season already, the NFC contender Carolina Panthers made San Francisco pay, putting together two unanswered drives to win 10-9 in Week 10 after the Niners settled for three straight field goals to start the game.

49ers score touchdown from inside red zone, which IS a deviation from the plan.

The 49ers Are the Ultimate Three-Phase Team

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San Francisco's special teams unit came up big again this week, punching in the last score of the game, which was the nail in the coffin for the Bucs.

The team got a lucky bounce as a muffed kickoff return was recovered by Kendall Hunter, who only had to hustle a few yards into the end zone. It was an outstanding effort play. But frankly, the coverage team was rocking and rolling for all four quarters leading up to this opportunity, helping to position the 49ers defense all day.

It was really a reward for their persistence.

Special teams is an unheralded phase that San Francisco prides itself on, no doubt deriving from the philosophy that a team is only as strong as its weakest link.

Their attention to the position group was apparent this offseason, as they made it a point to upgrade, so it's worth noting that it is indeed paying dividends. Not many teams in the NFL can say their special teams unit helps them win games, but the 49ers can.

This year, San Francisco is second in net yards per punt attempt (42.6), even though 51.1 percent of Andy Lee’s punts are returned, which is the sixth-most in the league. They also happen to be the best punt-and-cover team away from their home stadium, per NFL Team Rankings.

Their kickoff coverage has been flawless, not allowing a single score in 2013.

Best special teams play of the year for the 49ers? Best special teams play of the year for the 49ers.

Overall, Kap played a very good game—running, spreading the ball around to all of his receivers and challenging teams vertically. Just watching him operate, there was far less hesitation on his part and it also resulted in more success when it came to improvising, particularly on third down.

Kaepernick was attacking the defense back rather than allowing himself to be victimized, which we had seen earlier this season.

Against defensive stars in Lavonte David, Gerald McCoy, Darrelle Revis and Dashon Goldson, he could have very well been burnt. By no means was this an easy matchup. That being said, this game was very validating for Kap and, without doubt, a confidence booster as he leads the team down the final stretch of the season.

Entering the Last-Ever Game at Candlestick Park

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With only two weeks left in the regular season, the 49ers find themselves heading into Week 16, looking at their last-ever game at Candlestick Park.

It hasn’t been the most beautiful defense of home field in 2013, losing to Andrew Luck and the Indianapolis Colts, as well as the Carolina Panthers following a bye week where the 49ers should’ve been rested.

On the bright side, they did defeat Aaron Rodgers and the Packers in Week 1 and disposed of the St. Louis Rams and Seattle Seahawks in back-to-back weeks, ending on a high note versus their division rivals.

This coming week, on Monday Night Football, they’ll host Matt Ryan and the Atlanta Falcons in a rematch of the 2012-13 NFC Championship.